This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. SPECIFIC AIMS Primary Objective "To quantitate the change in melanoma intratumoral infiltrates by CD8+ cytotoxic T lymphocytes (CTL) after the administration of CP-675,206. This data will be used for hypothesis generation on the mechanism of action of CP-675,206.